The pressure of fluid supplied by a universal fluid distribution system may vary with a system requirement, climate, a supply source, and/or other factors, and in order to meet the transportation requirement of most terminal devices, requiring the fluid to be in line with a predetermined pressure and at or lower than the maximum capacity of a fluid regulator, the fluid regulator is implemented in these distribution systems to ensure that the requirement of the terminal devices is met.
FIG. 1 shows a conventional fluid regulator 100. The fluid regulator 100 usually includes an actuator 12 and a regulator valve 14.
The regulator valve 14 has a fluid inlet 30 for receiving fluid from, for example, a fluid distribution system and a fluid outlet 34 for transporting the fluid to a terminal device. The regulator valve 14 includes a valve port 28 disposed between the fluid inlet 30 and the fluid outlet 34. The transportation of the fluid from the fluid inlet 30 to the fluid outlet 34 has to be conducted through the valve port 28. The regulator valve 14 further includes a valve rod 26 and a valve flap 32. The valve flap 32 is disposed at an end portion of one end of the valve rod 26, located in the regulator valve 14, and the valve flap 32 and the valve rod 26 can be connected to one another. The valve flap 32 is adapted to move between a closed position, engaging the valve port 28, and an open position, spaced from the valve port 28, and the valve rod 26 is used for driving the valve flap 32 to move between the closed position and the open position.
The actuator 12 is coupled to the regulator valve 14 to ensure that the pressure at the fluid outlet 34 of the regulator valve 14, that is, the outlet pressure, meets a desired outlet pressure. The actuator 12 and the regulator valve 14 are in communication with each other and fluid is allowed to flow through. The actuator 12 includes a control spring 22, a shell 24, a diaphragm 18, an upper tray 16, and a lower tray 20. The shell 24 and the diaphragm 18 define a hole cavity that is in communication with the fluid outlet 34 of the regulator 14 and can allow the fluid to flow through, and the diaphragm 18 is used for sensing the outlet pressure of the regulator valve 14. The control spring 22 is disposed in the shell 24, and engages with the upper tray 16 at the top of the diaphragm 18. Therefore, the desired outlet pressure is set based on the control spring 22. The diaphragm 18 is further coupled to the valve rod 26 of the regulator 14, and the upper tray 16, the diaphragm 18, and the lower tray 20 are connected together through the valve rod 26 and a valve rod nut 36. The diaphragm 18 drives the valve rod 26 to move based on the sensed pressure, and the valve rod 26 drives the valve flap 32 to move together, so as to control opening and closing of the regulator valve 14, thereby adjusting the pressure of the fluid outlet 34.
When the regulator works normally, the pressure of the fluid outlet 34 rises over the desired pressure of the outlet, the diaphragm 18 senses a relatively large pressure so as to drive the valve rod 26 of the regulator to move, thus driving the valve flap 32 to reach the closed position of the valve port 28 to seal the valve port. The regulator is closed to prevent the pressure of the fluid outlet from rising.
As the regulator is used over time, a sealing effect between the valve flap 32 and the valve port 28 may be reduced, leakage may occur when the regulator is closed, and at this point, the pressure of the fluid outlet 34 may rise all the time, and may even be equal to the inlet pressure, or the pressure of the fluid outlet 34 fluctuates in a too large range, for example, a water hammer phenomenon, such that the pressure of the fluid outlet 34 suddenly rises. At this point, the force generated by the pressure of the fluid outlet 34 and acting on the diaphragm 18 may be completely transferred to the valve rod 26, the valve flap 32, and the valve port 28 of the valve element assembly, applying an extremely large stress to the valve rod, the valve flap, and the valve port, which may cause the valve rod, the valve flap, and the valve port to be deformed or even damaged so as to be dangerous.
Therefore, an actuator of a regulator and a fluid regulator are provided to prevent the valve element assembly from being deformed and damaged due to extremely large stress.